Question

Having a bit trouble with this. Can some one please help? Thanks

Answer 1

$2 - \sqrt{-4} - 3 + \sqrt{-16}$
$= 2 - i\sqrt{4} - 3 + i\sqrt{16}$
$= 2 - 2i - 3 + 4i$
$= -1 + 2i$

Answer 2

The square root of (-4) = square root of  (-1) x (4) = 2i

The square root of (-16) = square root of (-1) x (16) = 4i

So now you have the sum of  (2 - 2i) and (-3 + 4i).

The real part of the sum is (2 - 3) = -1

The imaginary part of the sum is ( -2i + 4i ) = +2i

The whole sum is    -1 + 2i .